The International Plant Propagators' Society exists to bring together all those with an interest in the many different facets of plant propagation and production.

The idea for preparing the current index began shortly after the publication of Volume 50 of the Proceedings. As International Editor, I contributed my time to assemble this index at no cost to the Society. All page references are to the first page of the article. When a plant name appears in the discussion following an article, the reference is to the first page of that article.

The current 50-year index uses the same four parts utilized in the first two index: 1) Contents [paper titles], 2) Author, 3) Plant Name, and 4) Subject.

The Plant Name Index was the most difficult to complete. It was my desire to have plants named as accurately as possible. With that in mind, Warren G. Roberts, University Arboretum, University of California, Davis, California was asked to review the Plant Name Index to check the spellings and correctness for plant names.

The format used in the Plant Name Index is as follows:

• Genus is spelled out the first time in the listing and abbreviated to the first letter thereafter. Genera of hybrid origin have an × (multiplication sign) before the generic name.
• Cultivars of hybrid or of unidentified origin are listed next after the genus.
• Species within the genus are listed next, each preceded by the letter abbreviation for the genus. Species of known hybrid origin have × inserted between the generic and specific names.
• Botanical subdivisions of the species, i.e. variety (var.), subspecies (ssp.), forma (f.), are found immediately after the species they belong with.
• Cultivars for a species are listed with the species.

The Subject Index is based primarily on the title of the article as listed in the Contents Pages. When the title as not sufficiently informative or when other important topics occupied a major part of the article, the topics for the Subject Index were taken from the text of the article. The subject categories have been increased to provide better cross referencing with the Plant Name Index and Contents Pages. For example, a paper titled "Influence of Daylength and Irradiance Level on Growth of the Stock Plants and Rooting of Betula utilis, Corylus maxima 'Prupurea' and Pinus mugo Cuttings" would be subject indexed under the following categories: Betula, Corylus, Cutting Propagation, Light, Photoperiod, Pinus, Research, Stock Plants.

I want to thank my wife, Patricia Heuser, for encouraging my interest and pursuit of this project. I express my appreciation for her patience and understanding during the long hours I was working on this index. Finally, I want to thank Dr. Chester M. Smith, Jr., Retired Assistant Professor Computer Science, Penn State University, for his advise, and training in data processing that made the preparation of this index feasible.